Systems and methods for flushing an assessment catheter

ABSTRACT

Devices systems and methods are disclosed for removing secretions from the lumen of a functional assessment catheter for the lungs. The system comprises a flushing unit configured to deliver a clearing fluid to the lumen of the pulmonary catheter to remove debris, secretions, or moisture from the lumen or sensors.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationNo. 61/774,322 (Attorney Docket No. 20920-769.101), filed Mar. 7, 2013,the full disclosure of which is incorporated herein by reference. Thepresent application is a continuation-in-part of U.S. patent applicationSer. No. 13/023,722, filed Feb. 9, 2011, which is a continuation ofInternational Patent Application No. PCT/US2009/056392 (Attorney DocketNo. 017534-005010PC), filed Sep. 9, 2009, which claims priority to U.S.Provisional Application No. 61/095,582 (Attorney Docket No.017534-005000US), filed Sep. 9, 2008, the full disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates generally to catheters and more specifically tocatheter apparatus and approaches for minimizing entry of secretions ordebris into or removal of secretions or debris from the catheter andmore particularly in those catheters that are used for assessingpulmonary function.

Chronic obstructive pulmonary disease is a significant medical problemaffecting 16 million people or about 6% of the U.S. population. Specificdiseases in this group include chronic bronchitis, asthmatic bronchitis,and emphysema. While a number of therapeutic interventions are used andhave been proposed, none are completely effective, and chronicobstructive pulmonary disease remains the fourth most common cause ofdeath in the United States. Thus, improved and alternative treatmentsand therapies would be of significant benefit.

Of particular interest to the present invention, lung function inpatients suffering from some forms of chronic obstructive pulmonarydisease can be improved by reducing the effective lung volume, typicallyby resecting diseased portions of the lung. Resection of diseasedportions of the lungs both promotes expansion of the non-diseasedregions of the lung and decreases the portion of inhaled air which goesinto the lungs but is unable to transfer oxygen to the blood. Lungvolume reduction is conventionally performed in open chest orthoracoscopic procedures where the lung is resected, typically usingstapling devices having integral cutting blades.

While effective in many cases, conventional lung volume reductionsurgery (LVRS) is significantly traumatic to the patient, even whenthoracoscopic procedures are employed. Such procedures often result inthe unintentional removal of healthy lung tissue, and frequently leaveperforations or other discontinuities in the lung which result in airleakage from the remaining lung. Even technically successful procedurescan cause respiratory failure, pneumonia, and death. In addition, manyolder or compromised patients are not able to be candidates for theseprocedures.

As an alternative to LVRS, endobronchial lung volume reduction (ELVR)uses endobronchially introduced devices which plug or otherwise isolatea diseased compartment from healthier regions of the lung in order toachieve volume reduction of the diseased compartment. Isolation devicesmay be implanted in the main airways feeding the diseased region of thelung, and volume reduction takes place via absorption atelectasis afterimplantation or via collapse by actively suctioning of the targetcompartment prior to implantation. These implanted isolation devices canbe, for example, self-expanding occlusive stents that prevent air flowin both directions or one-way valves that allow flow in the exhalationdirection only.

While a significant improvement over LVRS, ELVR can have a limitedtherapeutic benefit when the treated region in the lung is exposed tocollateral ventilation from adjacent regions. The lungs comprise aplurality of compartments, referred to as lung compartments or lobes,which are separated from one another by a double layer of enfoldedreflections of visceral pleura, referred to as fissures. While thefissures which separate the compartments are typically impermeable, inpatients suffering from COPD, the fissures are frequently incomplete,leaving a pathway for collateral airflow or inter-lobular collateralventilation. Such collateral airflow can result in the intrusion of airinto the isolated lung compartments treated by ELVR, thus reducing oreliminating the desired volume reduction.

Collateral flow to diseased lung compartments can be detected, forexample using the methods described in co-pending, commonly-owned U.S.patent application Ser. No. 11/296,591, filed on Dec. 7, 2005 (US2006/0264772A1) and Ser. No. 11/550,660, filed on Oct. 18, 2006 (US2007/0142742A1).

The catheter comprises a catheter body, and an expandable occludingmember on the catheter body. The catheter body usually has a distal end,a proximal end, and at least one lumen extending from a location at ornear the distal end to a location at or near the proximal end. At leasta distal portion of the catheter body is adapted to be advanced into andthrough the airways of a lung so that the distal end can reach an airwaywhich feeds a target lung compartment or segment to be assessed. Theexpandable occluding member, such as an inflatable balloon, is disposednear the distal end of the catheter body and is adapted to be expandedin the airway which feeds the target lung compartment or segment so thatsaid compartment or segment can be isolated with access provided onlythrough the lumen or catheter body when the occluding member isexpanded. Simultaneously, the expandable occluding member may add tocatheter function by centering the distal end of the catheter within theairway. In this state, inhaled air is precluded from entering thecatheter lumen, while exhaled air from the isolated lung compartment canexit only through the catheter lumen.

The exhaled air exits the proximal end of the catheter lumen, which iscoupled to an external console. The external console monitors thecharacteristics of the exhaled air, such as flow and pressure, andcommunicates the values associated with such characteristics to a user.If the flow and pressure decrease over time, a user may determine thatthe lung segment is not subject to collateral ventilation, and suchsegment is appropriately treated with ELVR.

While the use of these procedures can identify patients likely tobenefit from ELVR procedures, the need for improvements exists,particularly during assessment in lung passageways containing bodilysecretions, such as mucus. For instance, if mucus enters the catheterlumen, the air flow into the lumen will be impeded, thus interferingwith the monitoring function of the external console and may lead toerroneous results. Further, in catheters utilizing an inflatableballoon, the balloon might distend due in some part to bubbles formed bymucus. This causes the catheter, to lean into the passageway,potentially blocking the opening. Further, when an obturator is used tointroduce the catheter and is later withdrawn, the obturator may act asa syringe or piston and draw mucus into the catheter lumen.

For these reasons, it would be desirable to provide alternative andimproved methods and apparatus for functional lung assessment withinlung passageways containing secretions. In particular, it would bedesirable to provide methods systems and devices that enhance catheterfunctionality by keeping secretions out of the catheter lumen,inhibiting secretion build-up within the passageways, cleaningsecretions within the catheter lumen, or any combination thereof. Atleast some of these objectives will be met by the inventions describedherein below.

SUMMARY OF THE INVENTION

In one aspect, the present application discloses devices, systems andmethods for flushing or removing secretions or debris from a lumen of acatheter, such as a functional assessment catheter for the lungs. Thepulmonary catheter is capable of being introduced transtracheally intoan air passage of a lung segment. The pulmonary catheter comprises adistal end and a proximal end with a lumen disposed in-between.

In one aspect, the catheter may be modified to be connectable to aflushing unit that is connectable to a fluid source, wherein theflushing unit is configured to deliver a clearing fluid to the lumen ofthe pulmonary catheter to remove debris from the lumen. The flushingunit comprises a fixed volume fluid chamber connectable to the fluidsource and a fluid restrictive element configured to regulate thedelivery of the clearing fluid from the fluid chamber. The fluid chamberis configured to store a volume of the clearing fluid. The system maycomprise a control unit configured to control a state of the fluidrestrictive element

In one aspect, the control unit is configured to transform the fluidrestrictive element to a state whereby the fluid restrictive elementallows the clearing fluid stored in the fluid chamber to beinstantaneously released to flush the catheter.

In another aspect, the control unit is configured to transform the fluidrestrictive element to a state whereby the fluid restrictive elementallows a sustained release of the clearing fluid stored in the fluidchamber to flush the catheter over a period of time.

In yet another aspect, the flushing unit comprises two fluid restrictiveelements, wherein the control unit is configured to control the firstand second fluid restrictive elements. The control unit may beconfigured to transform the first fluid restrictive element to a statewhereby the first fluid restrictive element allows the clearing fluidstored in the fluid chamber to be instantaneously released to flush thecatheter, and to transform the second fluid restrictive element to astate whereby the second fluid restrictive element allows a sustainedrelease of the clearing fluid stored in the fluid chamber to flush thecatheter over a period of time.

Other aspects of the invention include methods corresponding to thedevices and systems described above. One method for assessment of a lungcompartment comprises the steps of providing a pulmonary diagnosticsystem comprising an endobronchial pulmonary diagnostic device connecteda pulmonary catheter, said catheter having at least one measuringcomponent connected with the device; introducing the distal end of thecatheter to a compartment of a lung; generating measurement datacharacterizing the compartment of the lung with the pulmonary diagnosticsystem; and delivering a clearing gas from a flushing unit to flush thepulmonary catheter.

This and other aspects of the present disclosure are described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Present embodiments have other advantages and features which will bemore readily apparent from the following detailed description and theappended claims, when taken in conjunction with the accompanyingdrawings, in which:

FIGS. 1 a through 1 d show exemplary embodiments of a catheter providinga component that diverts secretions away from the distal opening of thecatheter.

FIGS. 2 a and 2 b show a catheter comprising an element that couldcollect secretions away from the catheter opening.

FIG. 3 shows a catheter comprising an alternative embodiment that bothattracts and collects the secretions away from the catheter opening.

FIGS. 4 a and 4 b show another exemplary embodiment providing an elementthat attracts the secretions away from the distal opening of thecatheter.

FIGS. 5 a and 5 b show an alternative method of attracting secretions toa point distal to the catheter opening.

FIGS. 6 a through 6 d show a catheter embodiment comprising variouscovers.

FIG. 7 shows a cover for the distal tip that is incrementally removable.

FIG. 8 contemplates methods for enhancing assessment even when thedistal opening of the catheter is not centered within the lungpassageway.

FIG. 9 shows another embodiment to attract the secretions to a sitedistal from the catheter tip.

FIG. 10 shows another embodiment to attract the secretions to a sitedistal from the catheter tip.

FIG. 11 shows an alternative method of preferentially attracting thesecretions to a site away from the inner lumen of the catheter.

FIG. 12 contemplates a method for cleaning the inner lumen of thecatheter once secretions have actually entered the catheter.

FIG. 13 shows an alternative method of repelling the secretions bymodifying the distal tip of the catheter.

FIG. 14 shows a catheter attached to a syringe.

FIGS. 15 a-15 b show a catheter attached to flushing mechanisms.

DETAILED DESCRIPTION OF THE INVENTION

Although the detailed description contains many specifics, these shouldnot be construed as limiting the scope of the disclosure but merely asillustrating different examples and aspects of the disclosure. It shouldbe appreciated that the scope of the disclosure includes otherembodiments not discussed herein. Various other modifications, changesand variations which will be apparent to those skilled in the art may bemade in the arrangement, operation and details of the method, device,and system of the present embodiments disclosed herein without departingfrom the spirit and scope of the disclosure as described here.

Throughout the specification and claims, the following terms take themeanings explicitly associated herein unless the context clearlydictates otherwise. The meaning of “a”, “an”, and “the” include pluralreferences. The meaning of “in” includes “in” and “on.” Referring to thedrawings, like numbers indicate like parts throughout the views.Additionally, a reference to the singular includes a reference to theplural unless otherwise stated or inconsistent with the disclosureherein.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” is not necessarily to be construed as advantageous overother implementations.

The present invention deals with methods systems and devices forpreventing secretions from impeding the function of a pulmonaryassessment catheter, hereinafter referred to simply as a catheter.

The various catheter embodiments described herein may be used singularlyor in combination. In one aspect, secretions can be prevented fromimpeding the function of the catheter by preventing the secretions fromentering the catheter lumen. Additionally or alternatively, secretionsbuild-up in the airway could be prevented or inhibited. Additionally oralternatively, secretions that collect within the airway could beremoved. Additionally or alternatively, the secretions could be repelledaway from the distal tip of the catheter.

FIG. 1 a shows an exemplary embodiment providing an expandable elementthat attracts the secretions away from the distal opening of a catheter100 and precludes secretion entry into the catheter 100 during transportto the assessment site. Catheter 100 optionally comprises an expandableoccluding member near its distal end, for example an inflatable balloon101. A mesh 110 capable of forming a basket-like configuration isattached at a point proximal to the distal tip of the catheter 100, anddistal to the balloon 101. The mesh 110 is composed of a biocompatibleshape-memory material, for example nitinol. Optionally, the mesh 110 maycomprise a coating, for example, silicone, at least on some portionthereof. In its initial configuration, the mesh 110 forms a cover forthe distal opening of the catheter 100. The cover remains closed, asshown in FIG. 1 a, while the catheter 100 is being transported to theassessment site. Secretions will thus be precluded from entering thelumen of the catheter 100 during such transportation. The proximal endof the mesh 110 is coupled to an elongate component 111, for example awire or an obturator, configured to manipulate the mesh 110. Prior todeployment of the mesh 110, the elongate component 111 constrains themesh 110 and prevents the mesh from expanding to its shape memoryconfiguration. At the assessment site, the mesh 110 will be deployed byretracting the elongate component 111 and thereby releasing the mesh 110from constraint to expand to its shape memory. Upon deployment, the mesh110 obtains the configuration shown in cross section in FIG. 1 b. Inthis configuration, the secretions would be caught within the outerdiameter of the mesh 110, and would thus be diverted away from thedistal tip of the lumen. Further, due to the surface tension of thesecretions, the secretions would tend to pool within the mesh 110, andthus, secretion entry into the lumen would be delayed or eliminated.Simultaneously, the open configuration of the mesh 110 keeps the lumenof catheter 100 centered within the lung passageway, rather than leaningtowards a wall within the lung passageway.

Alternatively or additionally, the mesh basket can be contained withinthe lumen of catheter 100, as shown in FIG. 1 c. In this embodiment, thecatheter 100 comprises a mesh 120 in a collapsed configuration withinthe distal tip of the catheter 100 until the catheter 100 is moved tothe assessment site. Catheter 100 optionally also comprises a balloon101. The mesh 120 is composed of a biocompatible shape-memory material,for example nitinol. Optionally, the mesh 110 may comprise anair-impermeable coating, for example, silicone, at least on some portionthereof. The proximal end of the mesh 120 is coupled to an elongatecomponent 121, for example a wire or an obturator, configured tomanipulate the mesh 120. The elongate component 121 maybe containedwithin the lumen wall of catheter 100 (as shown in FIG. 1 c), or it maybe contained anywhere within or on the catheter 100. Prior toassessment, the mesh 120 is deployed. The mesh 120 forms a ball-likestructure of sufficient porosity to allow for air flow through the mesh120. Simultaneously, the secretions would tend to adhere to the outerdiameter of the mesh 120, and thus, secretion entry into the lumen ofcatheter 100 would be delayed or eliminated.

Alternatively, the mesh forms a funnel-like structure 130 that allowsair to be directed into the catheter lumen as shown in FIG. 1 d. In thisembodiment, catheter 100 comprises a mesh 130 in a collapsedconfiguration within the distal tip of the catheter 100 until thecatheter 100 is moved to the assessment site. The mesh 130 is composedof a biocompatible shape-memory material, for example nitinol.Optionally, the mesh 130 may comprise an air-impermeable coating 132,for example, silicone, at least on some portion thereof. The proximalend of the mesh 130 is coupled to an elongate component 131, for examplea wire or an obturator, configured to manipulate the mesh 130. Theelongate component 131 maybe contained within the lumen of catheter 100(as shown in FIG. 1 c), or it may be contained anywhere within or on thecatheter 100. Prior to assessment, the mesh 130 is deployed to assumeits shape memory of a funnel-like structure whose base is open to andengaged with the opening of catheter 100. In this embodiment, the mesh130 acts to simultaneously preclude secretion entry into the catheterlumen while directing air within the passageway into the lumen ofcatheter 100. The secretions would tend to adhere to the outer diameterof the mesh 130, and thus, secretion entry into the lumen of catheter100 would be delayed or eliminated. Simultaneously, when deployed, mesh130 with coating 132 acts to seal the passageway and center the catheter100 within the passageway such that the only outlet for air is throughthe funnel-like structure into the catheter lumen. Thus, in thisembodiment, the mesh 130 may replace the balloon 101 shown in previousembodiments.

FIG. 2 a shows an inflatable element 130 that could keep the secretionsaway from the opening of catheter 100. In one embodiment, the inflatableelement 130 is located distal to the balloon 101 on the catheter 100.During transport, the distal tip of the inflatable element 130 is in anun-inflated state and covers the opening of the catheter 100 as shown incross section in FIG. 2 a. When inflated, the inflatable element 130opens to reveal the lumen of catheter 100 as shown in cross section inFIG. 2 b. Simultaneously, when the element 130 is inflated open,secretions that have thus far accumulated are pushed outwards and awayfrom the lumen of catheter 100. Additionally, the inflatable element 130keeps the distal tip of the catheter 100 centered within the lungpassageway. Additionally or alternatively, the inflatable element 130sealingly engages the lung passageway walls to perform the function ofthe balloon 101.

FIG. 3 shows an alternative embodiment to that shown in FIG. 2. Thisembodiment, shown in cross section, contemplates a collapsible rigidelement 140, that is manipulated through elongate components such as awire 141 contained within or on the catheter 100. The present figureshows the wire 141 contained within the wall of catheter 100. The wire141 can be pulled back and forth by the user to open and close the rigidelement 140. In this configuration, secretions will again pool along orbehind the element 140, rather than into the lumen of catheter 100.

FIG. 4 a shows, in cross section, another exemplary embodiment providingan element that attracts the secretions away from the distal opening ofthe catheter 100, and precluding secretion entry into the catheter 100during transport to the assessment site. In this embodiment, the distaltip 200 comprises several strands 210 arranged to protrude radially fromthe distal tip 200. The distal tip 200 thus looks similar to a brushwith several bristles. The strands 210 are composed of any suitablebiocompatible material. The configuration of the strands 210 allows forair to flow into the lumen of catheter 100 during the assessment.Simultaneously, the secretions adhere to the strands 210 and away fromthe opening of the catheter 100. Optionally, the distal tip 200 of thecatheter 100 also comprises several small apertures 211. The apertures211 in the distal tip 200 of the catheter 100 facilitate air flow intothe catheter 100. Optionally, the distal tip 200 could be manipulatedwithin the passageway, for example in a backwards and forwards motion,to clean the area of assessment. Optionally, the strands 210 at thedistal end may or may not be of a uniform length, and the strands 210may form different cross sectional embodiments. Additionally, the distalsection of the catheter 100 maybe detachably coupled or permanentlyaffixed to the distal tip 200 of the catheter 100.

Additionally or alternatively, the strands 210 are connected to anelongate component contained within the catheter 100, for example a wireor obturator 212 as shown in FIG. 4 b. It is transported as such to theassessment site. At the assessment site, the component 212 with thestrands is deployed out of the catheter lumen and into the lungpassageway. In one aspect, the component 212 with the strands may beheld stationary at a point distal to the end of the catheter 100, todeflect the secretions. In another aspect, the component 212 with thestrands may be moved along the lung passageway to clean the lungpassageway and thereafter be held stationary at a point distal to thecatheter 100, or be retracted through the lumen of catheter 100.Additionally, the strands 210 at the distal end may or may not be of auniform length, and they may form different cross sectional embodiments.

FIGS. 5 a and 5 b show an alternative embodiment for attractingsecretions to a point distal to the catheter opening. In thisembodiment, tines 220 protrude longitudinally from the distal end of thecatheter 100. The tines 220 could be made of any biocompatible materialincluding nitinol, PTFE or silicone. During transport of catheter 100 tothe assessment site, the tines 220 are held closed, for example using aring 221 connected to a wire 222 contained within or on the catheter 100as shown in FIG. 5 a. At the assessment site, the tines 220 are opened,for example, by pulling on the wire 222 to retract the ring 221, asshown in FIG. 5 b. The tines 220 keep secretions from entering the innerlumen of the catheter 100, by repelling the secretions if hydrophobic,or by preferentially attracting the secretions if hydrophilic.

In another embodiment of the present invention, a cover could beprovided to prevent the secretions from entering the lumen of catheter100, as shown in FIGS. 6 a through 6 d. The catheter 100 comprises acover over the distal opening. Additionally, the catheter 100 comprisesa wire 311 running the length of the lumen of catheter 100, from theproximal end accessible by a user, to a cover at the distal end. Thewire 311 maybe soft or rigid. It may be contained within the lumen wallof catheter 100, or it may be contained anywhere within or on thecatheter 100. The cover remains over the distal opening of the catheter100 during the catheter's movement to the assessment site. Prior to orduring assessment, the cover is opened or closed by manipulating thewire.

For example, FIG. 6 a shows a catheter 100 comprising a flap cover 310,wherein one end of said cover is manipulatable by the wire 311. In aclosed position, the flap cover assumes the configuration as shown inposition (1). When the wire 311 is pulled, the flap cover 310 is opened,as shown in position (2) to allow air to flow into the catheter 100 forassessment.

Another example is provided in FIG. 6 b which shows a catheter 100comprising a soft cover 320 that can be pushed forward or retracted by awire 321. The soft cover 320 can be made of any flexible material, suchas a plastic film, that will provide little or no suction when it iswithdrawn through the lumen of catheter 100. During transport of thecatheter 100, the soft cover 320 covers the distal opening of thecatheter 100, thereby preventing or inhibiting secretion entry into thecatheter 100. Prior to or contemporaneous with assessment, the softcover 320 is manipulated via the wire 321, and the distal opening of thecatheter 100 is open to receive air flow for assessment.

Alternatively, the cover may encapsulate the distal opening of thecatheter 100, as shown in FIG. 6 c. In this embodiment, theencapsulating cover 330 may encase the opening of the catheter 100. Theencapsulating cover 330 is attached to the wire 331 and can be pushedout into the lung passageway for the assessment procedure.

In another embodiment, the cover may be a balloon 340 within the lumenof the catheter 100 as shown in FIG. 6 d. The balloon 340 is attached toan elongate component, such as a wire 341, of a small enough diameter tonot act as a syringe when being pulled out. When inflated, the balloon340 prevents secretion entry into the lumen of catheter 100. Duringassessment, it may be deflated and pulled back with the wire 341 toleave an open catheter lumen.

FIG. 7 shows a cover for the distal tip of the catheter 100 that isincrementally removable. The distal tip of the catheter 100 comprises alayered cover 340 with removable layers 345 made of a biocompatiblematerial. The distal tip of the catheter 100 may or may not beperforated. The layers 345 are incrementally removable through one ormore attachments, such as a wire 341 contained within the layers thatextends the length of the catheter 100 to the user. Additionally, thebiocompatible material may or may not be hydrophilic. In one embodiment,the distal tip of the catheter 100 may be transported to the assessmentsite, where the layers 345 are removed. In another embodiment, thelayers 345 may be removed incrementally during the assessment process.For example, in the embodiment with apertures in the catheter 100, ifsecretions were to impede the air flow into the catheter 100, several ofthe layers 345 could be removed to expose another set of apertures inthe catheter 100.

FIG. 8 contemplates methods for enhancing assessment even when thedistal opening of the catheter 100 is not centered within the lungpassageway, for example, through distension of the inflatable balloon101. In this embodiment, the catheter 100 comprises apertures 410 withinthe catheter wall at the distal end. The apertures 410 may be of anysize or shape and may be organized in any pattern while maintainingcatheter 100 integrity. For example, the apertures 410 are elongate toallow the catheter 100 to maintain structural rigidity. The apertures410 are scattered throughout the circumference of the catheter 100, sothat even if some of the openings of the catheter 100 are plugged withsecretions, other openings will remain clear. Additionally, even if oneportion of the catheter 100 leans against the lung passageway wall, theopposite portion will have some of the apertures 410 exposed to thegases contained within the lung passageway. Thus, the assessmentfunction of the catheter 100 will not be impaired.

FIG. 9 shows another embodiment to attract the secretions to a sitedistal from the tip of the catheter 100. In this embodiment, an elongatecoil 510 is deployed from the distal tip of the catheter 100. Theelongate coil 510 can be made of any biocompatible shape memorymaterial, for example, nitinol. While transporting catheter 100 to theassessment site, the elongate coil 510 is contained within the lumenwall of catheter 100 in a straight-line configuration, such as a wire511. The wire 511 is then pushed out of the distal opening and coils toassume the configuration of the elongate coil 510 within the lungpassageway. Alternatively, the elongate coil 510 could be contained in acompressed, but coiled state within the lumen wall of the catheter 100while transporting to the assessment site. The elongate coil 510 couldthen be deployed into the lung passageway, where it would expand intothe lumen wall. The secretions along the wall passageways would adhereto the points of the elongate coil 510 in contact with the lungpassageway wall rather than to the catheter 100. Simultaneously, theinner diameter of the elongate coil 510 is open and allows enough air toflow into the assessment catheter 100. In another embodiment, theelongate coil 510 would cover a portion of the distal end of thecatheter 100.

FIG. 10 shows another embodiment to attract the secretions to a sitedistal from the tip of the catheter 100. In this embodiment, a flat coil520 is deployed from the distal tip of the catheter 100. The coil can bemade of any biocompatible memory-shape material, for example, nitinol.During catheter transport to the assessment site, the coil is containedwithin the lumen wall of catheter 100 in a straight-line configurationsuch as a wire 521. The wire 521 is then pushed out of the distalsurface and assumes the shape of a flat coil 520 within the lungpassageway. The flat coil 520 is then deployed into the lung passageway,where it would expand to the diameter of the lung passageway. Thesecretions along the lung passageway walls would adhere to the points ofthe flat coil 520 in contact with the lung passageway wall.Simultaneously, the inner diameter of the flat coil 520 would besufficiently open to allow for enough air flow into the assessmentcatheter 100.

FIG. 11 shows an alternative method of preferentially attracting thesecretions to a site away from the inner lumen of the catheter 100. Thedistal tip of the catheter 100 comprises an addition, for example, acoating or a pad or a paper cone, of an absorbent material 610. Theabsorbent material 610 can comprise any biocompatible, absorbentmaterial, and may or may not be expandable. The coating of absorbentmaterial 610 may end proximal to the distal tip of the lumen duringassessment. Secretions at the assessment site will thus be absorbed bythe absorbent material. As some secretions are absorbed by the absorbentmaterial 610, it cohesively attracts more secretions. Thus, secretionsthat thereafter reach the assessment site will be attracted to theabsorbent material, 610 rather than to the wall of catheter 100.

FIG. 12 shows an alternative method of repelling the secretions bymodifying the distal tip of the catheter 100. Traditionally, cathetersare coated with PEBAX, which adheres to secretions. The presentembodiment contemplates coating the distal tip with a hydrophobicsubstance 910, for example PTFE, to divert secretions away from thelumen of catheter 100.

FIG. 13 contemplates a method for cleaning the inner lumen of thecatheter 100 once secretions have actually entered the catheter 100. Inthis embodiment, the inner lumen of the catheter 100 comprises anelongate inner component, such as a wire 710, extending from theproximal end to the distal end, terminating at the distal end in aradial element 711. The radial element 711, shown in cross section inFIG. 13, has an outer diameter that is substantially similar to orslightly less than the inner diameter of the catheter 100. If secretionsenters the inner lumen of the catheter 100, the radial element 711 ismoved in a distal direction and past an amount of secretions that is tobe removed, and subsequently back in a proximal direction, therebymoving the secretions contained within the lumen in a proximaldirection, and optionally removing the secretions from the proximal endof the catheter 100. Alternatively, the radial element 711 is moved in adistal direction to push secretions contained within the lumen in adistal direction.

Another embodiment of the present invention contemplates alternativeobturators. In this embodiment, the obturator has a different shape tosimultaneously keep enough secretions out while at the same timeexerting little or no negative pressure at the distal end of thecatheter, thereby allowing the obturator to retract without drawingsecretions. For example, the cross section of the obturator could beflower shaped, star shaped or cross shaped. Additionally oralternatively, the obturator could be hollow. A hollow obturator mayadditionally be used as an aspiration port to aspirate the lungpassageway during transport, assessment, or any combination thereof.

Additionally or alternatively, the obturator is configured to act likean Archimedes screw. Whenever the distal opening of the catheter 100encounters secretions, the screw-shaped obturator will channel thesecretions through the catheter 100 and away from the site of theassessment.

In another embodiment of the present invention, one or more elementscould be stored within or on the distal tip of the catheter to dry orotherwise preclude secretion build-up within the catheter. For example,a heating element may be used to dry the airway. Alternatively,medications that minimize mucus formation (.e.g., a mucolytic drug) maybe coated on the catheter tip. The drug can diffuse slowly out of thecoating into the surrounding tissue and provide extended release of adrug that can prevent or minimize mucus formation or breakdown the mucusthat is secreted by the local tissue.

In another embodiment of the present invention, at least one extra lumenand corresponding port may be provided to aspirate the passageways, drythe passageways, flush the passageways, aerate the passageways,introduce a mucolytic drug into the passageways or any combinationthereof. Alternatively, aspiration could occur via the existing lumensand ports. This is facilitated via a modified proximal portion of thecatheter that is configured to introduce a fluid, (e.g., air) into thecatheter. The introduced fluid would emerge from the distal end of thecatheter with sufficient force to dry (if air or another gas is used) orpush secretions that accumulate near or around the catheter mouth.

An example of such a modified proximal portion is shown in FIG. 14. Inthis embodiment, the proximal portion of the device is configured toreceive a fluid-propelling mechanism 800. The fluid-propelling mechanism800, such as a syringe, comprises a propellant portion 810 at theproximal end of the device, and a release valve 830 at the distal end ofthe device, and a pressurizer 820 therebetween. The propellant portion810 further comprises an intake port 801, a chamber 802 and a plunger803. A fluid is introduced into intake port 801 and is drawn into thechamber 802 in a syringe-like manner by pulling on plunger 803. Intakeport 801 is configured to be one-way or closeable to preclude fluid fromexiting intake port 801 from chamber 802. Thereafter, the plunger 803 ispushed into chamber 802 to direct fluid into the pressurizer 820. Thefluid is precluded from exiting the distal end of mechanism 800 byrelease valve 830, which remains in a closed position in a defaultstate. Simultaneously, the fluid is held under pressure in thepressurizer 820. When secretions are to be removed, release valve 830 isopened. The fluid, which has been accumulated under pressure in thepressurizer 820, will exit the mechanism 800 and enter the catheter 100.The fluid will have sufficient force that upon exiting the distal end ofcatheter 100, it will dry or move secretions accumulating around thecatheter end.

In another embodiment, a catheter 100 is configured to maintainstructural rigidity during transport without the use of an obturator. Inanother embodiment, the tip of catheter 100 is configured to be angularto enhance air flow into the catheter lumen. In another embodiment, theballoon 101 is inflated with a fluid, such as saline, to provide addedstability. This will aid the catheter 100 to be centrally maintainedwithin the lung passageway. Alternatively, the balloon 101 ismanufactured to be structurally symmetrical when inflated.

Another embodiment of the present disclosure is shown in FIGS. 15 a-15b. In this embodiment, the proximal portion of the catheter 100 isconfigured to be connectable to a flushing element 1000. The flushingelement 1000 is configured to deliver a clearing fluid to the lumen ofthe catheter 100 to remove debris, secretions, or moisture from thelumen or sensors. In one embodiment the flushing element 1000 isconfigured to be connectable to the proximal end of the catheter 100.The flushing element 1000 may alternatively be integrated into theproximal end of the catheter 100.

In one embodiment, the distal end of the flushing element 1000 comprisesone or more intake ports 1001 configured to connect the flushing element1000 to a fluid source such as a pump, a pressurized gas chamber, a walloxygen unit, or any other fluid source. In one embodiment the flushingelement 1000 is configured to be connectable to multiple fluid sourcessimultaneously. In one embodiment, the intake port 1001 is configured tobe one-way or closeable to preclude fluid from exiting the intake port1001. The flushing element 1000 comprises a pressure regulator 1010distal to the intake port 1001 configured to regulate the pressure andflow of fluid from the fluid source into the flushing element 1000. Theflushing element 1000 further comprises a release valve 1030 at thedistal end of the device and a pressurizer 1020 between intake port 1001and release valve 1030. The pressurizer 1020 is a rigid chamber of fixedvolume configured to store the clearing fluid and act as a flushcapacitor. Pressurizer 1020 may comprise a variable release safety valve1050 configured to allow the release of pressure from the system. In oneembodiment a flow restrictive element 1040 is located between thepressure regulator 1010 and the pressurizer 1020. The clearing fluid maybe any biocompatible fluid including oxygen, nitrogen, carbon dioxide,or any other biocompatible fluid.

In one embodiment, fluid is precluded from exiting the distal end offlushing element 1000 by release valve 1030, which remains in a closedposition in a default state. Simultaneously, the fluid is held underpressure in the pressurizer 1020. When secretions are to be removed,release valve 1030 is opened. The fluid, which has been accumulatedunder pressure in the pressurizer 1020, will exit the flushing element1000 and enter the catheter 100. The fluid will have sufficient forcethat upon exiting the distal end of catheter 100, it will dry or movesecretions accumulating around the catheter end.

In another embodiment, the release valve 1030 is a flow restrictiveelement controlled by a control unit. Control unit is configured to openand close the release valve 1030. Release valve 1030 may be a solenoidvalve wherein the control unit comprises a solenoid. In one embodimentthe control unit is configured to transform release valve 1030 to astate whereby the release valve 1030 allows the clearing fluid stored inthe pressurizer 1020 to be instantaneously released to flush thecatheter 100 (not shown). In another embodiment, the control unit isconfigured to transform release valve 1030 to a state whereby therelease valve 1030 allows a sustained or continuous release of theclearing fluid stored in the pressurizer 1020 to flush the catheter 100over a period of time to prevent secretion or debris buildup.

In one embodiment, the flushing element 1000 may comprise multiplerelease valves 1030 connected in parallel. In one embodiment flushingelement 1000 comprises an instantaneous release valve and a sustainedrelease valve. If multiple release valves are present, a single controlunit may separately control all release valves 1030. Alternatively, eachrelease valve 1030 may be controlled by separate control units. Releasevalve 1030 may be configured to have a closed state, an openinstantaneous release state, and a partially open sustained releasestate, wherein the control unit is configured to transform the releasevalve 1030 to allow instantaneous or sustained release of fluid. Forexample, in one embodiment, the instantaneous release of fluid and thesustained release of fluid may be performed in tandem, where one releasevalve maintains a partially open sustained release state to continuouslyrelease the fluid to prevent or minimize secretion or debris buildup,contemporaneously, the operator may instantaneously release the fluid tofurther flush the catheter 100. Alternatively, the instantaneousflushing and sustained flushing may be performed in sequence.

In another embodiment, the release valve 1030 may be variably opened toallow adjustable release of fluid. Control unit may further beconfigured to control pressure regulator 1010, safety valve 1050, flowrestrictive element 1040, or the selection of fluid source.

Any or all of the above embodiments may be combined or replaced withmedication prior to the assessment procedure.

While the above is a complete description of various embodiments, any ofa number of alternatives, modifications, and equivalents may be used inalternative embodiments. Therefore, the above description should not betaken as limiting the scope of the invention as it is defined by theappended claims.

What is claimed is:
 1. A pulmonary diagnostic system, comprising: apulmonary catheter capable of being introduced transtracheally into anair passage of a lung segment, wherein the pulmonary catheter comprisesa distal end and a proximal end with a lumen disposed in-between; and aflushing unit connectable to a fluid source, wherein the flushing unitis configured to deliver a clearing fluid to the lumen of the pulmonarycatheter to remove debris from the lumen.
 2. The system of claim 1,wherein the flushing unit comprises a fixed volume fluid chamberconnectable to the fluid source, wherein the fluid chamber is configuredto store a volume of the clearing fluid.
 3. The system of claim 2,wherein the flushing unit further comprises a first fluid restrictiveelement configured to regulate the delivery of the clearing fluid fromthe fluid chamber and a control unit configured to control a state ofthe first fluid restrictive element.
 4. The system of claim 3, whereinthe control unit is configured to transform the first fluid restrictiveelement to a state whereby the first fluid restrictive element allowsthe clearing fluid stored in the fluid chamber to be instantaneouslyreleased to flush the catheter.
 5. The system of claim 3, wherein thecontrol unit is configured to transform the first fluid restrictiveelement to a state whereby the first fluid restrictive element allows asustained release of the clearing fluid stored in the fluid chamber toflush the catheter over a period of time.
 6. The system of claim 2,wherein the flushing unit further comprises: a first fluid restrictiveelement configured to regulate the delivery of the clearing fluid fromthe fluid chamber; a second fluid restrictive element configured toregulate the delivery of the clearing fluid from the fluid chamber; anda control unit configured to control the first and second fluidrestrictive elements, wherein the control unit is configured totransform the first fluid restrictive element to a state whereby thefirst fluid restrictive element allows the clearing fluid stored in thefluid chamber to be instantaneously released to flush the catheter, andwherein the control unit is configured to transform the second fluidrestrictive element to a state whereby the second fluid restrictiveelement allows a sustained release of the clearing fluid stored in thefluid chamber to flush the catheter over a period of time.
 7. The systemof claim 1, further comprising a sensor connectable to the catheter,wherein the clearing fluid delivered by the flushing unit is configuredto clear the debris from the sensor.
 8. The system of claim 1, whereinthe flushing unit further comprising a safety valve.
 9. The system ofclaim 2, wherein the flushing unit further comprising a pressureregulator configured to regulate the pressure of the clearing fluid fromthe fluid source.
 10. A method for assessment of a lung compartmentcomprising the steps of: providing a pulmonary diagnostic systemcomprising an endobronchial pulmonary diagnostic device connected to apulmonary catheter, said catheter having a proximal end and a distalend, and at least one measuring component connected with the device;introducing the distal end of the catheter to a compartment of a lung;generating measurement data characterizing the compartment of the lungwith the pulmonary diagnostic system; and delivering a clearing fluidfrom a flushing unit to flush the pulmonary catheter.
 11. The method ofclaim 10, wherein the clearing fluid is delivered at a constant rate toflush the pulmonary catheter over a period of time.